# 作者：陈睿-cruise
# 2025年02月09日08时51分03秒
# 2979386061@qq.com
import random
def generate_num(num):
    str1='1234567890abcdefghijklmnABCDEFGHIJKLMN'
    code=''
    for i in range(num):
        index=random.randint(0,len(str1)-1)
        code+=str1[index]
    return code
print(generate_num(4))